iOS (formerly iPhone OS) is a mobile operating system developed by Apple Inc. for its iPhone, iPad, and iPod Touch products. It is the second most widely used mobile operating system in the world after Android.
iOS is the operating-system kernel of the iOS family of mobile operating systems, and its core component. Its graphical user interface is based on the Core Animation API and is built with the Cocoa Touch framework. Applications for the iPhone, including web apps and native apps, are written with Cocoa or a variant called Objective-C.
iOS is designed to be finger-friendly, using direct manipulation with multi-touch gestures such as swiping and pinching. Applications can be downloaded from the App Store, which is the only sanctioned source for iOS applications.
iOS versions up to and including version 6 are backward compatible with devices running earlier versions of the operating system. Version 7 introduced a complete redesign of the user interface with a focus on minimalism, as well as support for 64-bit processors and Apple’s CarPlay.
In addition to traditional features such as maps, local search, camera and game center, iOS also supports Bluetooth, 3G cellular data, Push notifications, and iCloud, which allows users to share photos, music, games, emails and other data between compatible Apple devices.
iOS also addresses security concerns by means of sandbox protection, sandboxing applications and data, and requiring signed applications. Built-in security and encryption features protect data on devices as well as in transit to and from the cloud.
Overall, iOS is a powerful mobile operating system, with control over both security and the applications available on the device. It is a capable platform on which to create mobile applications and is quickly becoming one of the most popular operating systems for both consumers and enterprise users.